首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   553篇
  免费   28篇
  国内免费   14篇
电工技术   46篇
技术理论   1篇
综合类   57篇
化学工业   5篇
机械仪表   1篇
建筑科学   106篇
矿业工程   11篇
能源动力   8篇
轻工业   224篇
水利工程   15篇
石油天然气   3篇
无线电   15篇
一般工业技术   30篇
冶金工业   41篇
自动化技术   32篇
  2024年   1篇
  2023年   18篇
  2022年   20篇
  2021年   40篇
  2020年   26篇
  2019年   36篇
  2018年   25篇
  2017年   28篇
  2016年   16篇
  2015年   12篇
  2014年   50篇
  2013年   38篇
  2012年   26篇
  2011年   30篇
  2010年   30篇
  2009年   31篇
  2008年   26篇
  2007年   24篇
  2006年   25篇
  2005年   27篇
  2004年   9篇
  2003年   6篇
  2002年   7篇
  2001年   8篇
  2000年   9篇
  1999年   6篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1994年   1篇
  1990年   1篇
  1988年   1篇
  1987年   1篇
  1985年   3篇
  1984年   1篇
  1981年   1篇
  1965年   1篇
  1964年   2篇
  1960年   1篇
  1959年   2篇
  1957年   1篇
  1954年   1篇
排序方式: 共有595条查询结果,搜索用时 93 毫秒
31.
Divorce and the Housing Movements of Owner-Occupiers: A European Comparison   总被引:1,自引:1,他引:0  
Divorce usually carries a range of economic consequences for both men and women, the housing situation of the ex-partners being among the most important ones. So far, however, the housing consequences of this life event, and in particular the way these are influenced by institutional arrangements, have been somewhat of a neglected topic. This paper focuses on one aspect of this process, more specifically the impact of divorce on tenure changes of homeowners, using comparative panel data for 12 European countries. It is concluded that although divorce significantly raises the odds of experiencing a tenure change for homeowners in all countries under consideration, this process is fairly similar across European welfare states. While institutional arrangements mitigating the economic consequences of divorce for women do not seem to explain much variation between countries, cross-national differences in tenure changes for homeowners are partly influenced by social housing policies and the extent of family support.  相似文献   
32.
冯立军  冯圆圆 《山西建筑》2010,36(10):223-225
从住房建设规划入手,探讨规划的基本框架以及调控保障性住房建设采取的措施,分析其中存在的问题和原因,并给出相关改进建议,以充分发挥住房建设规划的作用,促进和谐社会的建设。  相似文献   
33.
浅谈湖北农村饮水安全工程的准公益属性及对策   总被引:1,自引:0,他引:1  
陈楚珍 《中国水利》2010,(13):46-48
农村饮水安全工程纳入准公益性项目进行建设和管理。对确保工程“建得成、管得好、用得起、长受益”起着至关重要的作用。阐述了农村饮水安全工程的准公益属性,分析、研究了目前湖北省农村饮水安全工程未纳入准公益性项目管理而面临的一些问题,提出了相应的对策与建议。  相似文献   
34.
《Journal of dairy science》2022,105(1):453-467
Separation of the cow and calf shortly after birth is a common practice on commercial dairy farms around the world, but there are emerging concerns about this practice among citizens and other stakeholders. Continuous improvement of on-farm management practices in collaboration with dairy sector stakeholders increases the likelihood that farming systems evolve in a way that is consistent with societal expectations. Few commercial dairy farms provide extended cow-calf contact, and there is little understanding of how dairy farmers view this practice. This study examined the views of New Zealand dairy farmers toward providing cow-calf contact, particularly the barriers to adopting such a system in a seasonal-calving pasture-based dairy system. Standard farm practice in New Zealand is to remove the calf from the cow around 24 h (but could be up to 48 h) after birth. These conventional farmers (n = 63) were randomly selected from the database of all dairy farmers in New Zealand and telephone-interviewed using a semistructured interview format. Their responses to questions about providing cow-calf contact (defined as contact beyond the standard practice of 48 h) were analyzed using thematic analysis. Three major themes of concern were identified by these farmers about providing cow-calf contact as follows: (1) poor animal welfare, especially the risk of mastitis in the dam, inadequate colostrum for the calf, increased stress from delayed separation, and lack of shelter for calves while outdoors with the cow; (2) increased labor and stress on staff; and (3) system-level changes required, including infrastructure and herd management. Many of these concerns stemmed from challenges related to the nature of large-scale seasonal-calving pasture-based dairy systems, where a large number of calves are born in a short period of time and may be exposed to inclement weather in late winter in some areas. Several small-scale farmers (n = 4) providing cow-calf contact for longer than standard practice of 48 h were also interviewed; all permitted contact for at least 4 wk. These farmers also felt that animal welfare and health were important, and that this was promoted in their cow-calf contact systems. Concerns about colostrum and mastitis, for example, were not raised by these farmers, but they did agree that additional infrastructure and shelter were important considerations for cow-calf contact systems. Some conventional farmers expressed cognitive dissonance in that they theoretically preferred cow-calf contact but could not see it being realistic or practical to implement. Farmers currently providing longer cow-calf contact may be a useful resource for better understanding of how practical and economical cow-calf contact systems could be adopted on commercial pastoral dairy farms.  相似文献   
35.
Barrows (n=164) and gilts (n=249) from crosses of a Pietrain homozygous halothane recessive (Pi nn) and two Pietrain homozygous dominant (Pi NN-a and Pi NN-b) sire lines with Landrace×Large White NN sows, were used to study the effect of terminal sire and pre-slaughter treatment on meat quality and animal welfare. The pigs from each of the two farms where they were finished were delivered to the abattoir in two batches differing in the pre-slaughter conditions. A total of 90 pigs (54 NN and 36 Nn) were assigned to a long pre-slaughter treatment (6 h transport and 14.5 h lairage) and 89 (57 NN and 33 Nn) to a short pre-slaughter treatment (4.5 h transport and 2.5 h lairage) in Farm 1, and 118 (65 NN and 53 Nn) to the long (7 h transport and 14 h lairage) and 114 (66 NN and 48 Nn) to the short pre-slaughter treatment (1.5 h transport and 2 h lairage) in Farm 2. In Farm 1, heart rate of 3 NN and 3 Nn gilts was recorded throughout loading and transport and blood samples from 5 NN and 5 Nn were collected before loading and after transport to measure cortisol, creatine phosphokinase (CPK) and lactate dehydrogenase (LDH). Carcasses were classified and commercial cutting was carried out. At 24 h, meat quality was assessed on the Longissimus thoracis muscle by measuring electrical conductivity (PQM), colour (Minolta CR 200 and Japanese scale), pHu and drip losses. Halothane carriers showed a higher mean heart rate and higher increase in CPK levels (P<0.05) after transport in the short pre-slaughter treatment than halothane free pigs. No effect was observed in cortisol or LDH values. Pi NN-a sired pigs had a higher live and carcass weight (P<0.001) and loin depth (P<0.05), but lower killing out percentage (P<0.01) and leg yield (P<0.01) compared with the progeny of the other two terminal sires. Gilts were leaner (P<0.001), had a higher killing out percentage (P<0.001) and higher yields of primal cuts (P<0.001) compared with barrows. Pi nn sired pigs had poorer meat quality (higher PQM values in both farms, P<0.01) than Pi NN-a sired pigs. Long pre-slaughter treatment resulted in darker meat (P<0.01) in both farms and in higher pHu (P<0.001) in Farm 1 than short pre-slaughter treatment. Conversely, pigs subjected to the short pre-slaughter treatment showed higher PQM values (P<0.01) in Farm 1 and higher PSE percentage (P<0.05) in both farms compared to the ones subjected to the long pre-slaughter treatment. These results suggest that Pietrain halothane free sire lines could produce similar results on carcass quality to halothane carriers, without compromising meat quality and welfare.  相似文献   
36.
Conventional husbandry systems for pork production are scrutinized by members of the general public as well as the scientific community. As a response, alternative forms of pig production, such as outdoor housing, organic farming and environmental enrichment are gaining interest. The question arises whether these production systems are indeed able to improve the welfare and health status of the animals, and whether these production systems alter production characteristics and meat or carcass traits. Measures of poor welfare have been described, but evaluating overall welfare is difficult. Certain parameters of alternative housing will improve welfare in some ways but, simultaneously, other welfare problems are inflated, and the weighting of each of these problems is very subjective. Alternative housing systems allow pigs to display species‐specific behaviour and decrease the occurrence of abnormal behaviours by acting on several parameters: indoor versus outdoor housing, floor space/density, floor type, and provision of bedding or other types of environmental enrichment. Evaluating alternative housing systems should be done by looking at all the welfare‐improving factors and the cost of alleviating welfare‐decreasing problems in a given production system. Data in the literature on growth, meat and carcass traits in alternative production systems, are inconsistent, indicating that other factors can play an important role. However, as equal, or in some cases even better, performance can be attained in certain production systems that meet concerns of animal welfare scientists and members of the general public, alternative production forms may be considered preferable. Copyright © 2005 Society of Chemical Industry  相似文献   
37.
The public has become increasingly interested in the welfare of food animals, but the food animal industries possess few mechanisms for public engagement. Here we present results from a web-based forum designed to allow stakeholders to share views on controversial issues in dairying. In response to the question “Should dairy calves be separated from the cow within the first few hours after birth?” participants were able to indicate “yes,” “no,” or “neutral” and either write a reason in support of their view or select reasons provided by other participants. Four independent groups of participants were recruited (a total of 163 people); 31% said they had no involvement in the dairy industry; the remaining 69% (with some involvement in the industry) were students or teachers (33%), animal advocates (13%), producers (11%), veterinarians (9%) and other dairy industry professionals (3%). Overall, little consensus existed among participants across groups; 44% chose “yes,” 48% “no,” and 9% “neutral.” Responses varied with demographics, with opposition to early separation higher among females, animal advocates, and those with no involvement with the dairy industry. A fifth group was recruited at a dairy industry conference (an additional 28 participants); 46% chose “yes,” 32% “no,” and 21% “neutral.” Across all 5 groups, opponents and supporters often referenced similar issues in the reasons they provided. Opponents of early separation contended that it is emotionally stressful for the calf and cow, it compromises calf and cow health, it is unnatural, and the industry can and should accommodate cow-calf pairs. In contrast, supporters of early separation reasoned that emotional distress is minimized by separating before bonds develop, that it promotes calf and cow health, and that the industry is limited in its ability to accommodate cow-calf pairs. These results illustrate the potential of web-based forums to identify areas of agreement and conflict among stakeholders, providing a basis for the development of practices that address shared concerns.  相似文献   
38.
From Robert Q. Pollard's national leadership in deafness and mental health service delivery, advocacy, research, and training and his innovative multidisciplinary mental health traineeship program exclusively for deaf individuals to his establishment of a vibrant special interest section on deafness within APA's Division of Rehabilitation Psychology, he has led the way to providing full access to the profession and to the services of the profession for deaf individuals. His commitment to and effective advancement of a psychology open to and appropriately serving deaf individuals and other persons with disabilities substantially advances psychology in the public interest and fulfills our discipline's highest aspiration: to advance human welfare. This journal discusses the life and contributions of Robert Q. Pollard which enabled him to win the Psychology in the Public Interest Award in 1994. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
39.
Due to the incompleteness of animal genome sequencing, the analysis and characterization of serum proteomes of most farm animals are still in their infancy, compared to the already well-documented human serum proteome. This review focuses on the implications of the farm animal serum proteomics in order to identify novel biomarkers for animal welfare, early diagnosis, prognosis and monitoring of infectious disease treatment, and develop new vaccines, aiming at determining the reciprocal benefits for humans and animals.  相似文献   
40.
This paper examines the exposure to homelessness of socially marginalised groups to understand better the applicability of, and limits to, welfare regime analysis. A vignette methodology is deployed in six European countries to interrogate and compare responses to marginalised groups at high risk of homelessness, including people with substance misuse problems, ex-offenders, young people excluded from the family home, migrants and women fleeing domestic violence. Evidence suggests that a range of values embedded in national political cultures—including familialism, social cohesion, individuality, personal responsibility and personal liberty, as well as egalitarianism—impact on models of intervention and outcomes for specific marginalised groups in ways which cannot be straightforwardly predicted from conventional welfare regime analysis.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号